The grinding of particulate matter has involved a number of different approaches all of which present varying problems. Grinders in the prior art typically use blades or impellers to mechanically break down granular material into smaller pieces. However, this mechanical breakage is limited to the interaction of the blades or impellers upon the granular material. Accordingly, it is an objective of the present invention to create an environment which is influenced by impellers but does not require direct contact by the impellers upon the particulate matter to greatly reduce size.
Also in the prior art, grinders have been developed which grind material in a water or liquid environment in order to achieve a reduced particle size. However, water or liquid processing creates problems such as the leaching of soluble solids from the granular material and also creates the high energy problem of removing the water or liquid once the granular material is ground into powder. Accordingly, a further objective of the present invention is the provision of a granular material grinder that reduces particle size without the use of a water or liquid as a carrier.
U.S. Pat. No. 2,752,097 to Lecher discloses a grinder for producing ultra fine particles which creates vortexes around rotating paddle wheels which causes particles to strike the outside wall. However, Lecher is a low volume system that creates high heat that must be cooled with a large air volume. In addition, the Lecher environment is subject to stresses that may damage the equipment. Accordingly, a further objective of the present invention is to produce a granular material grinder that does not emphasize particle collision with the inside of the chamber or impellers and has a lower operating temperature.
The market place is demanding materials that are microground and yet their chemical composition is not changed. For example, even slight changes in chemical compositions of pharmaceutical products or dietary supplements may inactivate the chemical composition or physical characteristic. Accordingly, a still further objective of the present invention is to control the operating parameter such that the temperature, carrier gas, and mechanical interaction do not damage these critical commercial products.
Another objective of the present invention is the provision of a method and process for grinding granular material that is economical and safe.
These and other objectives will become apparent from the following description.